WHAT are ladder fuels? A fuel ladder or ladder fuel is a Fire Service term for live or dead vegetation that allows a fire to climb up from the ground level landscape or forest floor and into the tree canopy. Common ladder fuels include tall grasses, shrubs, and tree branches, both living and dead.
DO you need to cut down trees? No! Trees are important habitat elements, but we need to remove ladder fuels around them and your home. Make sure your trees ARE healthy and free of dead wood. The ladder fuel problem can be corrected by providing a separation between vegetation layers. Within the defensible space area, a vertical separation of three times the height of the lower fuel layer is recommended. For example, if a 3ft tall shrub is growing beneath a redwood tree then 9ft would be the recommended separation distance. This could be accomplished by removing the lower branches, reducing the height of the shrub, or both.
WHAT else can be a ladder fuel? Ladder fuels come in many shapes and sizes including dry debris in gutters, woodpiles, wooden fences, and outdoor structures. Efforts should be made to ensure they’re separated, and clearance is maintained around them to prevent the spread of fire to your home. Surface and ladder fuel is almost always necessary to allow fire to spread vertically into a trees canopy. Defensible space breaks up the continuity of fuel both horizontally and vertically, to interrupt the spread of fire to your home.
Remember: The local vegetation is coming out of dormancy into new spring growth. With late rains into May initial efforts to cut back and maintain ladder fuels will need to be repeated after new growth occurs for at least the next couple months.
Learn more by visiting srcity.org/WildfireReady and click on A Guide to Sustainable Defensible Space and Homeowner’s Guide to Fire Safe Landscaping under the Property Owner Resource Library.